Facile Modification of Natural Bentonite as a Cationic Dyes Removal Yusuf Mathiinul Hakim1, b), Risfidian Mohadi2, a), Idha Royani3, c), Mardiyanto4, d)
1 Department of Environmental Science, Graduate School Sriwijaya University, Palembang, 30139, Indonesia.
2 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Sriwijaya University, Palembang, 30662, Indonesia.
3 Department of Physics, Faculty of Mathematics and Natural Sciences, Sriwijaya University, Palembang, 30662, Indonesia.
4 Pharmaceutical Department, Faculty of Mathematics and Natural Sciences, Sriwijaya University, Palembang, 30662, Indonesia.
a) Corresponding author: risfidian.mohadi[at]unsri.ac.id
b) yusufmathiinul191[at]gmail.com
c) idharoyani[at]unsri.ac.id
d) mardiyanto[at]mipa.unsri.ac.id
Abstract
The existence of bentonite is massively explored for a broad spectrum of applications. Optimization of bentonite was carried out through various modification methods to increase adsorption capacity. In this study, optimization of bentonite from Pacitan, Indonesia was carried out by pillarization method using Sodium (Na+) and Ammonium (NH4+) ion which affected to increasing the layer size of bentonite structure effect to increased adsorption capacity. The structural changes are indicated by an XRD spectra shift in the peaks range of 20[degree]-28[degree] due to differences in cations. The FTIR spectra confirmed a specific shift in wavelength of 3433 cm-1 due to the size of the cations. The results of the adsorption selectivity showed that bentonite-based adsorbents tended to readily adsorb Malachite Green in a mixed solution of cationic dyes (Rhodamine B and Malachite Green). Evaluation of the adsorption of Bentonite, Bentonite-Na, and Bentonite-NH showed an enhancement in capacity adsorbed of 100 mg.g-1, 116.279 mg.g-1, 526.316 mg.g-1 against Rhodamine B, respectively, and 109.890 mg.g-1, 123.457 mg.g-1, 128.205 mg.g-1 against Malachite Green, respectively. The kinetic studies display adsorption mechanism follows a pseudo-second order model. The thermodynamic parameters show that the reactions occur spontaneously and are endothermic.
